Skip to main content

Full text of "The manufacture and properties of iron and steel"

See other formats

TABLE IX-E. "Waste Gases from Keverberatory Furnaces.
Interval from charging furnace to taking tests.	No. of Tests.	CO,	CO	O
Less than. 20 minutes ........	17	10.8	4.9	4.2
	18	11 9	8.9	2.9
1 hour to 2 hours .............	6	11.8	7.5	0.5
	7	10.6	7.2	1.1
	6	9.8	4.2	5.4
True average .........	54	11.0	5.0	3.0
The results are so nearly uniform, that we may take the average to find the loss of heating power due to the escape of unturned. CO and also the loss of heat by the excess of air or oxygen. The results are given in Table IX-F, the loss from excess of oxygen being calculated on the assumption that the gases leave the boiler at a temperature of- 250 C.480 F. As already explained, the operation cannot be conducted for the benefit of the boiler, for the proper heating of the steel is the first consideration, but there is room for improvement when over one-fifth of all the power is wasted by non-combustion.
TABLE IX-F. Calculations on Waste Gases from Eeverberatory Furnaces.
	Kind of Gas		
	Average	2 h. 30 m.	3h,30m.
Coffisi-^oap-ceSt:::: -tlon     1  0   percent.... Loss from GO per cent ___ Loss from O  per cent ___ Total loss per cent ..... .	11.0 3.0 5.0 21.5 3.C	10.6 7.2 1.1 27.8 0.5	9.8 4.2 5.4 20,8 3.3
	25.1	28.3	24.1
(d) Continuous furnaces.-A continuous furnace is a rever-beratory furnace, where the blooms or billets are fed in at the flue end, pushed toward the firebox and drawn when they reach the hottest part. The pieces are hot when they reach the vicinity of the fire, and, therefore, the combustion of the fuel is facilitated, as the flame coming over the bridge wall is never cooled by freshly charged blooms, as in the intermittent fur-